The question possibly (unintentionally) mis-represents the position. The following is the quotation from the news item indicated in the question:
Prosecutors allowed to join ‘Million People March’—De Lima
By Jamie Elona, INQUIRER.net
11:05 am | Monday, August 26th, 2013
MANILA, Philippines – Justice Secretary Leila de Lima said prosecutors were allowed to join the “Million People March” calling for the abolition of the Priority Development Assistance Fund or “pork barrel” Monday.
“Our prosecutors have the right to join any peaceful assembly and express their sentiments on, and support to, any legitimate cause, such as abolition of the pork barrel,” De Lima said in a text message.
The event pushed through despite President Benigno Aquino III’s announcement last Friday that it was time to abolish the pork barrel system.
As of posting time, Superintendent Orlando Abellera Mirando Jr. said the number of participants was estimated at 60,000.
[The actual times of the event/march are not stated in the news article, but my answer is based on OP's statement that "the event was from 9am to 2pm.".]
The news item was written/posted at 11:05 am and reported that:
Justice Secretary ... [had previously] said prosecutors were allowed to join the [march].
It went on to report her words from a text message as:
“Our prosecutors have the right to join any peaceful assembly and express their sentiments on, and support to, any legitimate cause, ...”
What we do not know is when she sent that text message - but clearly it was some time prior to 11:00 am because the news item had to be written and posted. So, in fact, we do not know whether the text message was sent before or after the march started.
In any case:
The Justice Secretary's message said "Our prosecutors have the right ..." (present tense). It is clearly an on-going right and there is no indication that it is a new right as of the time of the message.
The first paragraph of the news item is reporting what the Justice Secretary had previously 'said'/written. It was not - as the question appeared to me to suggest - an announcement at 11:00 am of what was then permitted. It was merely a report of a past event - her statement.
I venture to suggest, moreover, that the news item was using, not the past tense, but the subjunctive form of the verb.
Hence the question appears to be based on a false assumption and/or on a mis-reading of the news item.